Vehicle battery packs may include a plurality of battery cells combined in series and/or in parallel to supply power to propel a vehicle. Battery cells that are combined in series increase output voltage of the battery pack while battery cells that are combined in parallel increase the amp-hour rating of the battery pack. Individual battery cells within the battery pack may from time to time output a voltage that is different from other battery cells of the battery pack. Additionally, the charge storage capacity of some battery cells within the battery pack may be greater or less than the charge storage capacity of other battery cells within the battery cell pack. However, the output capacity and storage capacity of a battery pack may be increased when all battery cells within a battery pack are operated at substantially the same level of charge.
One way to provide substantially equivalent charge between battery cells of a battery pack is to monitor battery cell charge and increase or drain charge of individual battery cells that are not at a desired charge level. However, the possibility of battery pack degradation may increase if battery cell charge is routed to a charge monitoring and charge balancing board that is remote from the individual battery cells. Further, the possibility of battery pack degradation may increase when the battery pack is liquid cooled or if liquid enters the battery pack unintentionally. Therefore, it may be desirable to provide a battery pack that includes charge monitoring and balancing with reduced possibility of battery pack degradation.
The inventor herein has recognized the above limitations and has developed an approach to address them. In one approach, a battery pack, comprising: a plurality of non-aqueous electrolyte battery cells; a liquid cooling circuit including a liquid heat transfer medium, the liquid cooling circuit in thermal communication with at least one of the plurality of non-aqueous electrolyte battery cells; electrical circuitry in electrical communication with the plurality of non-aqueous electrolyte battery cells; and a fluid resistant over mold encapsulating at least a portion of the electrical circuitry away from the liquid heat transfer medium.
By over molding conductors with a fluid resistant medium within a liquid cooled battery pack, it may be possible to reduce degradation within a battery pack. For example, it may be possible to reduce battery pack degradation via a low pressure thermoplastic injection over molding of conductors. The over mold may provide and/or maintain separation between conductors, and it may also reduce the possibility of electrical communication between different conductors or mechanical components such as heat sinks, structural hardware, mounting hardware, and housings that could be referenced to another potential, ground for example. In this way, over molding of selected components of a battery pack may be useful to reduce the possibility of battery pack degradation.
The present description may provide several advantages. Specifically, the approach may reduce battery pack degradation. Further, the approach may be applied to existing battery pack designs. Further still, the approach may provide resistance to fluids and electrical charge.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.